Speaker
Pablo Rodriguez-Fernandez
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P4.1108.pdf
45 EPS Conference
Conference onon Plasma
Plasma Physics,
Physics 2018, Prague, Czech Republic P4.1108
Explaining Cold-Pulse Dynamics in Tokamak Plasmas using Local
Turbulent Transport Models
P. Rodriguez-Fernandez1, A.E. White1, N.T. Howard1, B.A. Grierson2, G.M. Staebler3,
J.E. Rice1, X. Yuan2, N.M. Cao1, A.J. Creely1, M.J. Greenwald1, A.E. Hubbard1,
J.W. Hughes1, J.H. Irby1, F. Sciortino1
1
MIT Plasma Science and Fusion Center, Cambridge, USA
2
Princeton Plasma Physics Laboratory, Princeton, USA
3
General Atomics, San Diego, USA
It has been observed for more than twenty years that rapid edge cooling of fusion plasmas
triggers core electron temperature increases on timescales faster than a diffusion time, and
that the effect disappears as plasma density is increased. These temperature inversions have
been interpreted as strong evidence of nonlocal transport, and have therefore challenged the
local transport paradigm encapsulated in predictive electromagnetic drift-wave turbulent
transport models. In this work, the TRANSP power balance code coupled with the quasilinear
transport model TGLF-SAT1 [1], with a new saturation rule motivated by cross-scale
coupling physics and that captures the nonlinear upshift of the critical gradient, are shown to
fully describe the cold-pulse phenomenology [2]. The TGLF-SAT1 model is able to
quantitatively capture the prompt onset of the core electron temperature inversion, with a
magnitude that is qualitatively consistent with experimental trends, as well as the
disappearance at high-density. These new results provide further confidence that local
transport models can be used to reliably predict plasma behavior in future tokamaks, such as
ITER.
[1] G.M. Staebler et al., 2017 Nucl. Fusion 57 066046
[2] P. Rodriguez-Fernandez et al., Phys. Rev. Lett. 120, 075001 (2018)
This work was supported by U.S. Department of Energy Award No. DE-FC02-99ER5451, using Alcator C-Mod,
a DOE Office of Science User Facility. P.R.F. was also supported by U.S. Department of Energy Award No.
DE-SC0014264 and a La Caixa Fellowship.
